Effects of fiber motion on the acoustic behavior of an anisotropic, flexible fibrous material

The acoustic behavior of a flexible fibrous material was studied experimentally. The material consisted of cylindrically shaped fibers arranged in a batting with the fibers primarily aligned parallel to the face of the batting. This type of material was considered anisotropic, with the acoustic propagation constant depending on whether the dirction of sound propagation was parallel or normal to the fiber arrangement. Normal incidence sound absorption measurements were taken for both fiber orientations over the frequency range 140 to 1500 Hz and with bulk densities ranging from 4.6 to 67 kg/cu m. When the sound propagated in a direction normal to the fiber alignment, the measured sound absorption showed the occurrence of a strong resonance, which increased absorption above that attributed to viscous and thermal effects. When the sound propagated in a direction parallel to the fiber alignment, indications of strong resonances in the data were not present. The resonance in the data for fibers normal to the direction of sound propagation is attributed to fiber motion. An analytical model was developed for the acoustic behavior of the material displaying the same fiber motion characteristics shown in the measurements

Modularity and community structure in networks

Many networks of interest in the sciences, including a variety of social and biological networks, are found to divide naturally into communities or modules. The problem of detecting and characterizing this community structure has attracted considerable recent attention. One of the most sensitive detection methods is optimization of the quality function known as "modularity" over the possible divisions of a network, but direct application of this method using, for instance, simulated annealing is computationally costly. Here we show that the modularity can be reformulated in terms of the eigenvectors of a new characteristic matrix for the network, which we call the modularity matrix, and that this reformulation leads to a spectral algorithm for community detection that returns results of better quality than competing methods in noticeably shorter running times. We demonstrate the algorithm with applications to several network data sets.Comment: 7 pages, 3 figure

Bait Stations for Controlling Voles in Apple Orchards

Bait stations made with polyvinylchloride (PVC) pipe were compared with hand-broadcast applications of rodenticides for achieving long-term control of pine and meadow vole populations (Microtus pinetorum and M. pennsylvanicus, respectively) in two apple orchards in the mid-Hudson Valley of New York. The stations were constructed of three pieces of 1.5-in diameter PVC tubing joined together in the shape of an inverted T . Roofing shingles were placed over the entrances to some of the bait stations to encourage use by voles, while others were left uncovered. All stations were tied to trees, with no attempt to place them near runways or burrow entrances. Both pine and meadow voles consumed bait from the stations, regardless of whether the entrances were covered with roofing shingles. However, plugging of entrances with dirt was prevalent during winter in stations with roofing shingles. Vole activity and capture success were consistently lower on the plots with the two types of bait stations than on either the control or broadcast baiting plots 13, 26, 39, and 52 wk posttreatment, although the differences were not statistically different (p \u3e 0.05). The best control was achieved during the winter and early spring. Although spoilage of bait due to high humidity may limit its effectiveness in Eastern New York during the late spring and summer, the inverted T bait station provides a practical means of controlling voles in apple orchards during winter and early spring

Mixture models and exploratory analysis in networks

Networks are widely used in the biological, physical, and social sciences as a concise mathematical representation of the topology of systems of interacting components. Understanding the structure of these networks is one of the outstanding challenges in the study of complex systems. Here we describe a general technique for detecting structural features in large-scale network data which works by dividing the nodes of a network into classes such that the members of each class have similar patterns of connection to other nodes. Using the machinery of probabilistic mixture models and the expectation-maximization algorithm, we show that it is possible to detect, without prior knowledge of what we are looking for, a very broad range of types of structure in networks. We give a number of examples demonstrating how the method can be used to shed light on the properties of real-world networks, including social and information networks.Comment: 8 pages, 4 figures, two new examples in this version plus minor correction

Foraging ecology of the Philippine flying lemur (Cynocephalus volans)

Between August 1986 and September 1987, six Philippine flying lemurs (Cynocephalus volans) were observed foraging on 35 of 76 available species of trees, representing ≥12 families of ≥26 available families. Eight species were foraged on in amounts significantly greater than expected, given the tree\u27s abundance on the study area, and four were foraged on significantly less than expected. The foraging strategy of C. volans involved foraging many times during the night, for short duration, in several different species of tree each night. This strategy differed from that of other arboreal folivores

Movements of the Pine Vole (Microtus pinetorum) in Repopulating Orchard Habitat

Pine vole (Microtus pinetorum) populations cause significant damage to orchards and truck crops (e.g., Anthony and Fisher 1977, Biser 1967, Eadie 1954, Forbes 1972a). Yet their population structure and movement dynamics have received surprisingly little study (Smolen 1981). The scarcity of data may have been due in part to the former availability of Endrin as a highly effective control agent (e.g., Horsfall 1956b), but the appearance of Endrin-resistant populations (Webb and Horsfall 1967), the restrictions of use of chlorinated hydrocarbons, and the inclusion of pine voles in Integrated Pest Management programs have made the need for basic population data including immigration and emigration more acute. For example, demographic and movement information are universal components ofIPM programs, because management of populations is usually, and appropriately, based on demographic expectations, such as: how rapidly can pine vole populations increase? What densities can they achieve? How quickly do they recolonize depopulated areas? These are fundamental questions that require well-controlled field studies with specific aims. Other studies that bear upon the relationship of demographics and movement provide important background but fail, because of either design or analysis, to directly answer the above questions. See for example: Gentry (1968), VanVleck (1968), Gettle (1975), Gourley (1983), Renzullo (1983), Fitzgerald and Madison (1983)

EVALUATION OF A NEW DEER REPELLENT ON JAPANESE YEWS AT SUBURBAN HOMESTEADS

Jersey, an experimental deer repellent, was field tested against 2 commercial repellents on Japanese yews (Taxuscuspidata) near Ithaca, New York, during spring 1990. In Experiment 1, plots (nnn = 24) of 4 individually-potted yews were established, with 2 yews at each plot randomly treated with Jersey and 2 left as controls. Plots of 4 (1 x 4, n nn =12) and 16 (4 x 4, nnn = 2) plants were used in Experiment 2, with individual plants being treated with Jersey, Hinder”, or Big Game RepellentR (BGRR) or left as controls. Photographs with a grid matrix placed behind each h plant were taken from 2 m at the beginning of the experiment and after 10 weeks. These photographs were analyzed to produce a cover index of plant size. Plots were monitored weekly to record browsing. In Experiment 1 more control (46/48) than treated (7/48)plants were browsed (P \u3c 0.001). Controls were browsed earlier (x =1.7 wk) than treated yews (x = 4.4 wk, P \u3c 0.01). At the end of 10 weeks, control plants were reduced in size more than Jersey-treated plants (P \u3c 0.001). In Experiment 2, browsing rates did not differ among treatments in the 1 x 4 plots or 4 x 4 plots. However, controls were browsed more frequently than treated at both plot types (10/12 at 1 x 4, and 6/8 at 4 x 4 plots) (P \u3c 0.05). Browsing reduced control plants by 56.8% (n =10) in 1 x 4 plots and 47.2% (n = 6) in 4 x 4 plots. These results suggest that Jersey reduced deer damage to a shrub preferred by deer. Moreover, Jersey was as effective as BGRR and Hinder at reducing browsing. Experiments may need to be conducted under more severe conditions and over a longer time-period to separate efficacy of the 3 repellents

Evaluation of a New Deer Repellent on Japanese Yews at Suburban Homesites

Jersey, an experimental deer repellent, was field tested against 2 commercial repellents on Japanese yews (Taxus cuspidata) near Ithaca, New York, during spring 1990. In Experiment 1, plots (n = 24) of 4 individually-potted yews were established, with 2 yews at each plot randomly treated with Jersey and 2 left as controls. Plots of 4 (1 x 4, n = 12) and 16 (4 x 4, n = 2) plants were used in Experiment 2, with individual plants being treated with Jersey, HinderR, or Big Game RepellentR (BGRR) or left as controls. Photographs with a grid matrix placed behind each plant were taken from 2 mat the beginning of the experiment and after 10 weeks. These photographs were analyzed to produce a cover index of plant size. Plots were monitored weekly to record browsing. In Experiment 1 more control (46/48) than treated (7/48) plants were browsed (P \u3c 0.001). Controls were browsed earlier (i = 1.7 wk) than treated yews (i = 4.4 wk, P \u3c 0.01). At the end of 10 weeks, control plants were reduced in size more than Jersey-treated plants (P ≤ 0.001). In Experiment 2, browsing rates did not differ among treatments in the 1 x 4 plots or 4 x 4 plots. However, controls were browsed more frequently than treated at both plot types (10/12 at 1 x 4, and 6/8 at 4 x 4 plots) (P \u3c 0.05). Browsing reduced control plants by 56.8% (n = 10) in 1 x 4 plots and 47.2% (n = 6) in 4 x 4 plots. These results suggest that Jersey reduced deer damage to a shrub preferred by deer. Moreover, Jersey was as effective as BGRR and HinderR at reducing browsing. Experiments may need to be conducted under more severe conditions and over a longer time-period to separate efficacy of the 3 repellents

EVALUATION OF A NEW DEER REPELLENT ON JAPANESE YEWS AT SUBURBAN HOMESTEADS

Jersey, an experimental deer repellent, was field tested against 2 commercial repellents on Japanese yews (Taxuscuspidata) near Ithaca, New York, during spring 1990. In Experiment 1, plots (nnn = 24) of 4 individually-potted yews were established, with 2 yews at each plot randomly treated with Jersey and 2 left as controls. Plots of 4 (1 x 4, n nn =12) and 16 (4 x 4, nnn = 2) plants were used in Experiment 2, with individual plants being treated with Jersey, Hinder”, or Big Game RepellentR (BGRR) or left as controls. Photographs with a grid matrix placed behind each h plant were taken from 2 m at the beginning of the experiment and after 10 weeks. These photographs were analyzed to produce a cover index of plant size. Plots were monitored weekly to record browsing. In Experiment 1 more control (46/48) than treated (7/48)plants were browsed (P \u3c 0.001). Controls were browsed earlier (x =1.7 wk) than treated yews (x = 4.4 wk, P \u3c 0.01). At the end of 10 weeks, control plants were reduced in size more than Jersey-treated plants (P \u3c 0.001). In Experiment 2, browsing rates did not differ among treatments in the 1 x 4 plots or 4 x 4 plots. However, controls were browsed more frequently than treated at both plot types (10/12 at 1 x 4, and 6/8 at 4 x 4 plots) (P \u3c 0.05). Browsing reduced control plants by 56.8% (n =10) in 1 x 4 plots and 47.2% (n = 6) in 4 x 4 plots. These results suggest that Jersey reduced deer damage to a shrub preferred by deer. Moreover, Jersey was as effective as BGRR and Hinder at reducing browsing. Experiments may need to be conducted under more severe conditions and over a longer time-period to separate efficacy of the 3 repellents